An inhaler is a device mainly used for sterilization or treatment of bronchial tube, including an atomizing portion atomizing liquid and a conveying portion such as a mouthpiece for conveying the atomized liquid, allowing intake of the aerosol generated at the atomizing portion through one's mouth or nose, using the conveying portion such as the mouthpiece. Of these devices, inhaler in which medical liquid is turned to aerosol and conveyed for treatment is particularly referred to as an inhalation treatment device.
Generally, this type of inhaler has an air inhalation valve provided on the body of the device, so as to allow more efficient inhalation of aerosol without putting a burden on the user. The air inhalation valve is formed as a check valve attached to a wall of a flow path, so as to close a communicating hole provided on the wall of flow path forming a passage of air flow provided in the device. The air inhalation valve is for taking outer air into the flow path from the outside of the device, so that the user inhales air containing aerosol dispersed in the flow path.
A structure of the air inhalation valve is known, for example, from the disclosure of Japanese Patent Laying-Open No. 11-137688. According to the disclosure of Japanese Patent Laying-Open No. 11-137688, the air inhalation valve formed of an elastic member is attached on a lower surface of a cap body with an air inhalation opening, so that motion of the air inhalation valve is limited, to prevent excessive inhalation of the aerosol.
Patent Document 1: Japanese Patent Laying-Open No. 11-137688